As a host of environmental issues, such as global warming and the destruction of the ozone layer, continue to be talked about, industry, too has seen advances in energy efficiency through reduction in energy consumption. A large number of efforts are under way aimed at harmonizing industry and the environment, though at present no fundamental resolution of the problem has been put forward. In addition to this backdrop, reductions in energy consumption and in costs are major concerns because semiconductor manufacturing apparatuses such as heat treatment apparatuses as well as resist coating and development apparatuses consume large amounts of energy, and the clean rooms in which such apparatuses are operated are themselves costly environments. In semiconductor manufacturing plants, for example, the amount of energy consumed is tracked and managed using power meters for each semiconductor manufacturing apparatus on an individual (unit) basis.
When electric power is supplied to a semiconductor manufacturing apparatus and the equipment is activated, inevitably heat escapes through the walls of the equipment to the outside. However, if that heat is left as is, then the temperature inside the clean room will rise. At the same time, the temperature inside the clean room must be maintained at a constant temperature, such as for example 23° C., so the heat discharged from the equipment must be removed from the clean room. For this reason, the equipment is cooled by the flow of cooling water and/or the interior of a housing enclosing the equipment is ventilated.
However, even with such measures heat is discharged into the clean room via the housing, and that heat becomes part of the burden on the clean room temperature control system. That is, viewing the semiconductor manufacturing plant as a whole, processing the heat discharged from the equipment also consumes energy, and imposes corresponding costs. Therefore it follows that, even if it is possible to save energy on an individual equipment basis, then no energy savings can be realized for the semiconductor manufacturing plant as a whole if the amount of energy consumed in processing the heat discharged from the equipment is large.
Accordingly, in order to carry out optimum management of the plant as a whole including energy consumption and costs, it is necessary to track and to integrally manage the amount of energy consumed by the equipment as a whole, including the amount of heat discharged. Further, given that efforts to reduce emissions of CO2 (carbon dioxide) must be undertaken on a global scale, the amount of CO2 generated must be managed as well.